This invention concerns a process for combining liquid materials which are generally incompatible. More particularly, it concerns a process for combining, under pressure, a water-insoluble, liquid polyalkylene glycol derivative in relatively small amounts with a water-soluble, nonaqueous alkanolamine wherein the glycol derivative is repeatedly added under shear stress to the recycled alkanolamine in amounts proportionate to the total amount to be added until the desired colloidal dispersion is obtained.
The liquid materials to be combined in accordance with this process are not mutually soluble in any concentration. Because of the differences in polarity and molecular weight, they are not, under ordinary circumstances, even mutually miscible. Accordingly, to provide a stable, uniform colloidal dispersion, the components must be combined under strong mechanical forces. However, even at the low, additive amounts of the glycol derivative to be combined with the alkanolamine, a single pass at combining under pressure and applied shear stress the total amount of the derivative with the alkanolamine to obtain the desired dispersion has been unsuccessful. Repeated additions of proportionate amounts of the total amount of glycol derivative to be added to the alkanolamine must be made to provide a facile commercial process for preparing a stable dispersion of an alkanolamine containing the desired or additive amount of glycol or its derivative.
The dispersions of this invention are generally used in the gas treatment industry wherein recovered natural gas is sweetened by removal of hydrogen sulfide and/or carbon dioxide to reduce corrosiveness of the gas product. Alkanolamines and alkyl alkanolamines, are used as solvents in aqueous systems to absorb the acidic components of the gas. Occasionally, foaming develops in the aqueous alkanolamine system and anti-foam agents are added to overcome the problem. Polyalkylene glycols are widely used antifoam agents for alkanolamine sweeteners but attempts to combine the high viscosity, water-insoluble polyglycol derivatives with the nonaqueous alkanolamine at the formulator's plant have met with difficulties.